1. Field of the Invention
This invention relates to a data processing apparatus connectable to an information processing terminal via an interface.
2. Description of the Related Art
Recently, as the use of information processing terminals, such as personal computers or the like, has become widespread (for the sake of simplification, all such terminals are termed "PC"s), documents are generally formed using a PC. As a result, frequently a facsimile modem is connected to a PC, document data in the PC is directly converted into a facsimile image and the obtained image is transmitted. For that purpose, facsimile apparatuses, copiers, printers and peripheral apparatuses called multi-function apparatuses obtained by combining two or more of the foregoing apparatuses, which provide the same function as the facsimile modem, have been more and more used. The term "data processing apparatus" indicates a peripheral apparatus for such use in the following description.
Some recent PC's have the function of interrupting the electric power supply to a display device or an input/output terminal when there has been no input from a keyboard or a mouse for a certain time period, in order to reduce electric power consumption. The electric power supply for such a PC is, therefore, cut when the PC will not be used for a long time period, for example, at the end of the work day.
When using, for example, a facsimile apparatus as a data processing apparatus (peripheral apparatus), if the facsimile apparatus is set to an automatic reception mode or the like, the power supply of the apparatus is always kept turned on. In some facsimile apparatuses, in order to reduce the electric power consumption in a waiting state, the main power supply of the apparatus (for supplying electric power to respective units including a control unit) is turned off. Instead, the electric power is supplied only to a circuit for detecting call reception from a communication network, or to a circuit for detecting a key input from an operation unit of the apparatus. The main power supply is turned on when some cause for operating the apparatus has been detected.
When connecting a facsimile apparatus having such a power consumption reduction mode to a PC using an ordinary interface, if the facsimile apparatus is set to the power consumption reduction mode, the PC considers the facsimile apparatus to be turned off, and therefore communication (for remote control or the like) between the PC and the facsimile apparatus cannot be performed. If the power consumption reduction mode of the facsimile apparatus is released, communication with the PC can be performed, but the electric power consumption in the waiting state increases. Accordingly, the function (the power consumption reduction mode) of the apparatus cannot be effectively utilized.